There are many causes on how biodiversity is affected, and some of these causes are from humans including the spill of toxic chemicals in the Peconic Estuary and also high nitrogen levels from fertilizers and sewage treatment plants contributing to algal blooms. This eventually contributed fish kills due to the diminished oxygen levels. Amphipods are excellent biological indicators of the overall health and stability of an ecosystem because they are sensitive to pollution and are most abundant in clean water. We collected amphipods from the Peconic Bay and we will be able to sequence and DNA barcode the amphipods to see if we can identify any species that have never been barcoded before. The gene we are using is called Cytochrome c oxidase 1 (CO1). This gene can be used to identify organisms and differentiate between different species. The amount of amphipods and different types of amphipods we find we can then determine water quality in the area.